Naslov
Brackish Ostracods in Early/Middle Miocene and Holocene Lake Deposits ; are Analogies Acceptable?

Autori
Hajek Tadesse, Valentina

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Knjiga sažetaka, Abstracts Book / Horvat, M. ; Matoš, B. ; Wacha, L. - Zagreb : Hrvatski geološki institut, 2019, 83-84

Skup
6. hrvatski geološki kongres s međunarodnim sudjelovanjem

Mjesto i datum
Zagreb, Hrvatska, 09.10.2019. - 12.10.2019

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Domaća recenzija

Ključne riječi
Ostracoda, Miocene, Holocene, Non-marine, Paleoenvironmental reconstruction

Sažetak
Ostracods are small, bivalved crustaceans present in all aquatic and some terrestrial habitats. They are commonly preserved as fossils in sediments. In addition to ostracods ecological sensitivity to physical and chemical parameters, ostracods reflect the marine influence inside the paleolakes, and have great potential for the identification and reconstruction of transitional palaeoenvironments. The occurrence of indicative species, their proportion within the whole assemblage and the composition of the assemblage provide the important data for the interpretation of past changes (FRENZEL & BOOMER, 2005). This work studies the possible analogy between the brackish ostracods from Early/Middle Miocene lake deposits of Mt Požeška gora and ostracods from Holocene lacustrine deposits of the Adriatic coast. The aim of this study is to determine the changes in ostracod populations and occurrence and distribution of the first brackish ostracods by age and location of different paleolakes. According to GRIFFITHS & HOLMES (2000), post-Neogene ostracod assemblages/species can be compared with modern communities/taxa, allowing the understanding of ecological setting of past environments. Occurrence of brackish environmental marker taxa: Cyprideis torosa (JONES) and Cytheromorpha fuscata (BRADY) in Holocene deposits and Cyprideis sublittoralis POKORNÝ, Aurila sp., Leptocythere sp. and Amnicythere sp. in Miocene deposits, associated with halophile freshwater species indicates the dominant water type formed by the mixing of marine and fresh water and the variability in salinity of the investigated paleolakes. Findings of the mentioned brackish taxa coincide with research results of FRENZEL & BOOMER (2005) who have distinguished four ecological groups of brackish ostracods based on their salinity tolerance. There is no single formula or function which could be applied to all localities, but the exchange of marine and lacustrine palaeoenvironments in both Early/Middle Miocene deposits of Mt Požeška gora and Holocene deposits of the Adriatic coast is in accordance with climate changes, sea level changes and tectonic movements of the local or regional scale.

Izvorni jezik
Hrvatski

Znanstvena područja
Geologija

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